Caracterización física de fotorresistencias como dosímetros en radioterapia

Juan Román Raya; Isidoro Ruiz García; Catalina de los Ángeles Rodríguez Cano; Miguel Ángel Carvajal Rodríguez; Damián Guirado Llorente

doi:10.37004/sefm/2024.25.1.005

Authors

Juan Román Raya Hospital Universitario Virgen de las Nieves, Granada. https://orcid.org/0000-0002-7932-925X
Isidoro Ruiz García Universidad de Granada, Granada.
Catalina de los Ángeles Rodríguez Cano Hospital Universitario Torrecárdenas, Almería. https://orcid.org/0009-0000-2497-1766
Miguel Ángel Carvajal Rodríguez Universidad de Granada, Granada. https://orcid.org/0000-0003-0234-4758
Damián Guirado Llorente Hospital Universitario Clínico San Cecilio, Granada. https://orcid.org/0000-0002-3257-360X

DOI:

https://doi.org/10.37004/sefm/2024.25.1.005

Keywords:

Radiotherapy, dosimetry, light-dependent resistor, dose rate, angular response

Abstract

The quality control of radiotherapy treatments relies on the use of dosimetric sensors. Currently, ionization chambers and solid-state diodes, along with electrometers as reading systems, are the most commonly used systems for this purpose. This study investigates new dosimetric systems manufactured from commercial electronic devices, significantly reducing costs by not being specifically designed for use in radiotherapy. In particular, various models of commercial light-dependent resistors (LDRs) were analyzed as an alternative to existing dosimetric systems for dosimetry. A characterization of the response to ionizing radiation was conducted for different commercial models of LDRs associated with a clinical electrometer. Irradiations were performed under the usual conditions of radiotherapy treatments. Experimental results show that these LDR models can serve as an alternative to currently used dosimetric sensors, with the advantages of high sensitivity, smaller size, lower economic cost, and requiring lower polarization voltages.

References

ICRP. Prevention of accidents to patients undergoing radiation therapy. Publication 86. London: Elsevier; 2001.

Rosenfeld A. Electronic dosimetry in radiation therapy. Radiat Meas. 2007;41:134- 153. https://doi.org/10.1016/j.radmeas.2007.01.005

Carvajal M, Martínez-García M, Guirado D, Banqueri J, Palma A. Dose verification system based on MOS transistor for real-time measurement. Sens Actuators A Phys. 2016;247:269-276. https://doi.org/10.1016/j.sna.2016.06.009

Martínez-García M, Carvajal M, Torres del Río J, Jaksic A. Response to ionizing radiation of diferent biased and stacked pMOS structures. Sens Actuators A Phys. 2016;252:67-75. https://doi.org/10.1016/j.sna.2016.11.007

Ruiz-García I, Román-Raya J, Banqueri J, Palma AJ, Guirado D, Carvajal MA. Commercial photodiodes and phototransistors as dosimeters of photon beams for radiotherapy. Medical Physics. 2021;48(9). https://doi.org/10.1002/mp.14921

Román-Raya J, Ruiz-García I, Escobedo P, Palma AJ, Guirado D, Carvajal MA. Light-dependent resistors as dosimetric sensors in radiotherapy. Sensors 340 (Switzerland). 2020;20(6). https://doi.org/10.3390/s20061568

Kumar R, Sharma SD, Philomina A, Topkar A. Dosimetric characteristics of a PIN diode for radiotherapy application. Technology in cancer research & treatment.2014;13(4), 361-367. https://doi.org/10.7785/tcrt.2012.500388